Receiver



Feb. 2s, 1.928 1,660,615

S. HIRQSAWA RECEIVER Filed May 19, .1925

Patented Feb. 28, 1928.

near satesv treats rarer creme.

SHN IGHIL HIRQSAWA, GEE SENDAI-SHI, J'MAN.

Application filed May 19, 1925, Serial l lo. 31,390, and in Japan June 3, 192%.

The present invention relates to an electric trical attraction, between a conductive body and a semi-conductive body is relied upon to obtain the necessary vibrations and the invention comprises such a receiver having a vibrating arrangement comprising an electrical conductive disc and a semi-electrical conductive disc, these discs being relatively fixed and in intimate contact .with each other, the telephonic current being applied directly to the contacting surfaces of both said discs. The term semi-electrical conductive disc is intended to refer to materials such as slate, marble, agate and other iike non-hydroscopic materials.

The primary object of the invention is to obtain a sensitive receiver by utilizing the change of attractive force between said discs caused by thepassage of telephonic electric current through their contact surfaces, said force being of electrical origin and attributed to. so called electroadhesion eiiect. A further object is to produce a receiver by which the sound and voice can be exactly reproduced. A still further object is to simplify the. construction of the receiver and to cheapen the manufacturing cost.

. When an electrical current is passed through the contact surface of an electrical conductive disc and a semi-electrical conductive disc which are in intimate contact with each other, an attractive force acts between them, and consequently, if one of said discs is fixed and the other is free, the latter disc will be sensitively vibrated by the change of the current passed through the discs.

This invention has been accomplished by thesaid principle. By holding an electrical conductive disc and a semi-electrical conductive disc in intimate contact and passing the telephonic current through them, I have been able to construct a sensitive receiver for use in both wire and wireless telephony. Moreover, as this receiver has a high impedance,

it is especially convenient for Wireless telephone receiver of the type in which elec-' to the semi-electrical conductive disc 4 and the conductive disc 5 respectively.

When the telephonic current is supplied to the receiver the change of attractive force I between the discs causes the vibration of the disc 5 and'hence the sound is reproduced. When the resistance of the disc 4 is exceedingly large or the current is very weak, it is possibly necessary to cover the lower surface of the disc 4 or that surface which is not in contact with the disc 5 with some thin electric conductive material over its whole surface so as to distribute the current uniformly, by which a very sensitive receiver is produced. K 1 Instead of using a single circulardisc for the semi-conductive member as illustrated in the drawing, two or more separated disc members may be used. Generally speaking, it is advisable to usethin semi-conductive discs.

Thus, in my present invention, all small amounts of electric energy can be effectively utilized and useless distortions of voice or sound prevented whilst simplifying the construction of the receiver, and reducing remarkably the weight and the cost. 7

Having now described my invention, and

what I claim as new and desired to secure by Letters Patent, is-

1. A receiver of the character described, including relatively vibratory discs arranged in iiitimate contact with each other, .one of which is formed of conductive mate rial and the other of semi-conducting material, and means for supply telephonic current to each of said discs.

2. A receiver as claimed in claim 1, wherein the semi-conductive disc is coated-0n its non-contacting surface with conducting material.

' In testimony whereof, I have signed my name to this specification at Tokyo, Japan, this 29th day of April, 1925.

SHINIOHI nrnosawa. 

